###7.2
library(MASS)
data(Animals)
ani.m2<-lm(log(brain)~log(body),data=Animals,
           subset=!log(Animals$body)>8&log(Animals$brain)<6)
anim.m0<-lm(log(brain)~1,data=Animals,
            subset=!(log(Animals$body)>8&log(Animals$brain)<6))
anova(anim.m0,ani.m2)
anova(ani.m2)
summary(anim.m0)
##########7.3

cerrado<-read.table("aves_cerrado.csv",header=TRUE,sep=";",as.is=TRUE,rm.na=TRUE)
str(cerrado)
head(cerrado)
names(cerrado)
cerrado$urubu<-cerrado[,cerrado$urubu]
cerrado[is.na(cerrado==NA),]<-0

###7.4iris
data(iris)
names(iris)
lm.iris<-lm(iris$Sepal.Width~iris$Sepal.Length)
lm.iris.coef<-coef(lm.iris)
lm.iris.r2<-summary(lm.iris)
lm.iris.nopetal<-lm(iris$Sepal.Width~1)
lm.iris.nopetal.coef<-coef(lm.iris.nopetal)
lm.iris.nopetal.r2<-summary(lm.iris.nopetal)